1. Field of the Invention
This invention generally relates to printing systems which print out text stored in a buffer. More specifically, this invention relates to a system for controlling the output side-by-side printing of sequentially stored columns having varying line spacing requirements.
2. Description of the Prior Art (Prior Art Statement)
Representative of the closest known prior art are U.S. Pat. No. 3,952,852; the IBM Electronic "Selectric"* Composer; and U.S. patent application Ser. No. 680,562, filed Apr. 27, 1976 having Michael E. McBride as inventor and entitled Automatic Format Control for Text Printing System, now U.S. Pat. No. 4,086,660, issued Apr. 25, 1978. FNT *Registered Trademark, International Business Machines Corporation.
In U.S. Pat. No. 3,952,852 a system is disclosed having a keyboard and printer, a buffer and control, and a multi-column playout control unit. During setup for input keying, a beginning of memory code is stored in the buffer. Also, since the input printer is the same as the output printer, a tab field is set up for defining the printing locations of the columns. This can be set up by operator keying. For columns which are to be stored sequentially, but printed out in a side-by-side manner, the beginning of each column is defined by keying a column begin code. Along with this code are keyed and stored column mode and measure codes. Following the column begin, mode, and measure codes for each column, the column text is keyed and stored. At the end of the last column to be printed out in side-by-side relationship, a column end code is keyed and stored. Upon playout from the buffer, the thus established buffer memory is scanned when a column begin code is encountered. An operation flag is inserted into the memory after the first column begin code. After each column begin code except the first, a column marker code is inserted and scan continues. Upon detection of the column end code, scanning continues to the beginning of memory. When the operation flag is again detected, following characters and spaces are printed out in the defined mode until a carrier return is detected. If operation is not in the last column, the printer carrier is caused to tab rather than to return to the left margin, and a column advance operation is performed. This causes a column marker code to be written over the operation flag, and a scan of memory. The next detected column marker code is written over with a new operation flag. Playout proceeds as defined above until a carrier return is detected for the last column. The carrier is then caused to return to the left margin. The operations described continue until each column has been printed in its entirety. After printout of all columns, the column marker codes are flushed from memory.
As related to the instant application, also disclosed is the handling of a column having no further text to be printed when printout of a remaining column has not been completed. This is recognized by the system when a column begin or column end code is addressed by the operation flag following a column advance operation.
From the above, the side-by-side printout of sequentially stored text is fully disclosed. Included is the handling of empty columns, but different column indexing requirements are neither contemplated or disclosed.
The IBM Electronic "Selectric" Composer can be used to effect a side-by-side printout of sequentially stored columns. If line spacing is to vary from column to column, or within a column, the operator is required to key extra carrier returns or indexes during input keying and storage. During later playout, the system will recognize the extra index and carrier return codes and print the text out with the proper line spacing.
Based on the above, the IBM Electronic "Selectric" Composer is capable of performing a side-by-side printout of sequentially stored columns with proper line spacing. The problems with the use of this system for this purpose are that it is tedious and time consuming to key additional indexes and carrier returns, and the system is not capable later of adjusting text without removing the stored extra carrier return and index codes.
In the above-referenced McBride patent application, an automatic system is disclosed for controlling format during playout of a job made up of a number of pages recorded on a number of magnetic cards. At the beginning of a job and upon input keying, format information is keyed and stored in a text buffer. The format information is made up of tab set locations, measure length, index values, adjust modes, etc. For format changes prior to recording on a magnetic card, new format information is keyed and stored in the text buffer along with keyed text. Upon recording the text and format information on a card, the format information last in effect is transferred to a format buffer to control format until changed.
This prior art is relevant in that printer indexing (line spacing) requirements are stored and remain in effect from one segment to the next unless changed. One basic difference though, is that in the case of the instant application, the segments are different columns, whereas in the referenced McBride application the segments are different media. In addition to this difference, an important distinction is in the area of storing codes and later control. In the McBride application the codes are stored in a format buffer and remain in effect until different codes are detected in memory. The addition in the instant application is that index codes are system generated and stored in memory to control printing from column to column.
In summary, the above described art is relevant to varying degrees, but falls short of either anticipating or rendering the subject invention obvious. More specifically, the advance of the instant application is in the area of a system structured not only to store format information to control printing of following text, but to update the text buffer to control printing of sequentially stored text columns in a side-by-side format when the columns have different line spacing requirements. The advantages of this advance are reduced operator keying and attention, and automatic system updating of the text memory.
Other art considered relative to this application includes U.S. Pat. Nos. 3,611,308 and 4,032,900. Neither of these patents is considered any more pertinent than the art described above.